1. Field of the Invention
The present invention relates to an ion trap mass spectrometer, and more particularly, to an ion trap mass spectrometer using a cold electron source, in which cold electrons are produced at room temperature using an ultraviolet light emitting diode (UV LED), a microchannel plate (MCP) electron multiplier plate, and a channeltron electron multiplier (CEM), without using a thermionic source using a filament, and are applied to the mass spectrometer.
2. Discussion of Related Art
Generally, in a mass spectrometer, a process of ionizing gaseous molecules is required first to separate molecular ions according to masses of molecular ions and analyze components.
A method of ionizing gaseous molecules by bombarding with an electron beam is most frequently used. To produce the electron beam, a device for heating a filament at a high temperature to induce thermionic emission is most widely used.
The filament may be heated at a high temperature by flowing high current through a high-temperature metal such as tungsten or rhenium. However, due to high power consumption, battery power is rapidly consumed in a portable mass spectrometer. Further, a reaction of electron emission caused by a high temperature increase is slow, and thus the device using the filament is difficult to control in a mass spectrometer which is suitable to produce a continuous output electron beam and requires pulse ionization within a short time.